sendfilev(3EXT) Extended Library Functions sendfilev(3EXT)
NAME
sendfilev - send a file
SYNOPSIS
cc [ flag... ] file... -lsendfile [ library... ]
#include <sys/sendfile.h>
ssize_t sendfilev(int fildes, const struct sendfilevec *vec, int sfvcnt, size_t *xferred);
DESCRIPTION
The sendfilev() function attempts to write data from the sfvcnt buffers specified by the members of vec array: vec[0], vec[1], ... ,
vec[sfvcnt-1]. fildes is a file descriptor to a regular file or to a AF_NCA, AF_INET, or AF_INET6 family type SOCK_STREAM socket that is
open for writing.
This function is analogous to the writev() system call. See writev(2). However, instead of sending out chunks of data, sendfilev() can read
input data from data buffers or file descriptors.
The following is the sendfilevec structure:
typedef struct sendfilevec {
int sfv_fd; /* input fd */
uint_t sfv_flag; /* Flags. see below */
off_t sfv_off; /* offset to start reading from */
size_t sfv_len; /* amount of data */
} sendfilevec_t;
#define SFV_FD_SELF (-2)
To send a file, open the file for reading. Point sfv_fd to the file descriptor returned as a result. See open(2). sfv_off should contain
the offset within the file. sfv_len should have the length of the file to be transferred.
The xferred parameter is updated to record the total number of bytes written to out_fd.
The sfv_flag field is reserved and should be set to zero.
To send data directly from the address space of the process, set sfv_fd to SFV_FD_SELF. sfv_off should point to the data, with sfv_len con-
taining the length of the buffer.
PARAMETERS
The sendfilev() function supports the following parameters:
fildes A file descriptor to a regular file or to a AF_NCA, AF_INET, or AF_INET6 family type SOCK_STREAM socket that is open for
writing. For AF_NCA, the protocol type should be zero.
vec An array of SENDFILEVEC_T, as defined in the sendfilevec structure above.
sfvcnt The number of members in vec.
xferred The total number of bytes written to out_fd.
RETURN VALUES
Upon successful completion, sendfilev() returns total number of bytes written to out_fd. Otherwise, it returns -1, and errno is set to
indicate an error. xferred contains the amount of data successfuly transferred, which can be used to discover the error vector.
ERRORS
EAFNOSUPPORT The implementation does not support the specified address family for socket.
EPROTOTYPE The socket type is not supported.
EBADF The fildes argument is not a valid descriptor open for writing or an sfv_fd is invalid or
not open for reading.
EACCES The process does not have appropriate privileges or one of the files pointed by sfv_fd does not have appropriate
permissions.
EPIPE The fildes argument is a socket that has been shut down for writing.
EIO An I/O error occurred while accessing the file system.
EFAULT The vec argument points to an illegal address.
EFAULT The xferred argument points to an illegal address.
EINVAL The sfvcnt argument was less than or equal to 0. One of the sfv_len in vec array was less than or equal to 0, or
greater than the file size. An sfv_fd is not seekable.
EAGAIN Mandatory file or record locking is set on either the file descriptor or output file descriptor if it points at
regular files. O_NDELAY or O_NONBLOCK is set, and there is a blocking record lock. An attempt has been made to
write to a stream that cannot accept data with the O_NDELAY or the O_NONBLOCK flag set.
USAGE
The sendfilev() function has a transitional interface for 64-bit file offsets. See lf64(5).
EXAMPLES
The following example sends 2 vectors, one of HEADER data and a file of length 100 over sockfd. sockfd is in a connected state, that is,
socket(), accept(), and bind() operation are complete.
#include <sys/sendfile.h>
.
.
.
int
main (int argc, char *argv[]){
int sockfd;
ssize_t ret;
size_t xfer;
struct sendfilevec vec[2];
.
.
.
vec[0].sfv_fd = SFV_FD_SELF;
vec[0].sfv_flag = 0;
vec[0].sfv_off = "HEADER_DATA";
vec[0].sfv_len = strlen("HEADER_DATA");
vec[1].sfv_fd = open("input_file",.... );
vec[1].sfv_flag = 0;
vec[1].sfv_off = 0;
vec[1].sfv_len = 100;
ret = sendfilev(sockfd, vec, 2, &xfer);
.
.
.
}
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Evolving |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO
open(2), writev(2), libsendfile(3LIB), sendfile(3EXT), socket(3SOCKET), attributes(5)
SunOS 5.10 19 Apr 2004 sendfilev(3EXT)